Detection of Plutonium with the Microwave Plasma Continuous Emissions Monitor*

The first successful detection of plutonium with a continuous microwave plasma emissions monitor has been demonstrated. Seven plutonium emission peaks in the 362 366 nm and 449 454 nm ranges were clearly observed. The strongest peak was at 453.62 nm. This peak and five of the other plutonium peaks were easily distinguishable from possible interference from iron emission peaks with a spectrometer resolution of 0.1 rim. Introduction The microwave continuous emissions monitor has been demonstrated in-situ on the Mark II DC arc furnace[1]. This device has proven to be a robust monitor for trace metals in a hot, undiluted stream of furnace exhaust gas. Successful detection of various metals (Fe, Cr, Mg, Mn, Ba, etc.) in real time has been accomplished. Techniques for calibration and quantification of detected metals are also currently being investigated. The ultimate goal of this program is the development of a DC arc furnace system, capable of processing radioactive mixed wastes, such as those found in landfills across the DOE complex. Many of the buried waste sites have mixtures of hazardous wastes containing heavy metals and radioactive species such as plutonium. Due to public concerns with emissions from DOE treatment activities, a need has been identified to develop a technique to monitor for trace levels of plutonium in the treatment off-gas. Presently no real-time plutonium measurement technique exists. Therefore, testing of the microwave plasma continuous emissions monitor for the detection of plutonium has been a critical development task under this program. As a part of the milestone requirements for the 1994-1995 period, experiments were conducted in the summer of 1995 at the Battelle Pacific Northwest Laboratories (PNL) in Richland, WA, to detect plutonium with the microwave plasma continuous emissions monitor ' Supported by Battelle -Pacific Northwest Laboratory as part of the Landfill Stabilization Focus Area, Office of Technology Development, Environmental Management, U. S. Department of Energy.